1. Field of the Invention
The present invention relates to a display device and a method of manufacturing the display device.
2. Discussion of the Background
Recently, lighter and thinner monitors and television sets have been required. With this requirement, cathode ray tubes (CRTs) have been replaced with flat panel display devices such as liquid crystal displays (LCDs).
However, since an LCD may require a backlight unit to display an image, it may have a slow response speed and narrow viewing angle.
Since an organic light emitting display (OLED) does not have such problems, it is attracting increasing attention.
Generally, an OLED display includes a light emitting layer interposed between two electrodes. Electrons injected from one electrode and holes injected from the other electrode combine to form excitons, which emit energy and light.
Since the OLED display does not require an additional light source such as the backlight unit, the OLED display may have advantages of low power consumption, fast response speed, wide viewing angle, and high contrast ratio.
An OLED display may be a passive matrix or active matrix display depending upon its driving method.
The passive matrix display has a simple structure in which light emits from a region where two electrodes cross each other. On the other hand, the active matrix display has a structure in which light emits by current-driven pixels using thin film transistors (TFTs).
The active matrix OLED display may be a bottom emission type and/or a top emission type depending upon its light emission method. The bottom emission type display emits light toward a substrate where the TFTs are formed, and the top emission type display emits light away from the substrate where the TFTs are formed.
The bottom emission type display may have a low aperture ratio since light cannot pass through a portion where its TFTs and wires are formed. On the other hand, the top emission type display may have a high aperture ratio since the light emitting region is not associated with the space occupied by the TFTs and wires.
The above information disclosed in this background section is only for enhancement of understanding of the background of the present invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.